1. Field of the Invention
The present invention relates to a control device for an automatic transmission having an automatic mode and a manual mode.
2. Description of the Related Arts
Conventional selector devices for an automatic transmission with a manual mode can be classified into three operation modes.
For example, JP 2002-362180 A (see FIGS. 7, 11 and 12) discloses a selector device that has a manual mode position (M) for allowing a manual operation of a select lever. According to this selector device, the transmission gear of the automatic transmission is shifted up or shifted down through an operation of the select lever in the back-and-forth direction from the manual mode position. The operation path of the selector device is a so-called H type, and is formed so that the select lever operated to the drive position (D) can be operated to the manual mode position.
Also, JP 2000-283281 A (see FIG. 1) discloses a selector device which is a type of performing gear shifting through a selector switch provided at a steering wheel and a paddle switch and the selector device itself has no manual mode position for a manual operation. The selector switch is for changing the transmission gears of the automatic transmission to be in either one of the automatic mode or the manual mode, and is provided at the spoke of the steering wheel at the front side. The paddle switch is provided at the spoke of the steering wheel at the rear side, and includes a shift-up switch for shifting up the transmission gears and a shift-down switch for shifting down the transmission gears. In this case, a control device includes a manual mode controller that controls a manual mode.
Also, JP 2007-232093 A (see FIGS. 1 to 5 and 8) discloses a prior art which is a selector device shown in FIG. 8 thereof. This selector device includes a select pattern for an automatic operation path and a manual operation path, and a mode can be changed to a first manual mode at a drive position. The mode can be further changed to a second manual mode at the manual mode position. The selector device is electrically connected to a control device that includes a first manual mode controller and a second manual mode controller with a different transmission gear operation from the first manual mode controller.
However, according to the selector device disclosed in JP 2002-362180 A, when the mode is changed between the automatic mode and the manual mode, it is necessary to release a hand holding the steering wheel in order to operate the select lever from the drive position to the manual mode position, so that the operability is poor.
Also, according to the selector device disclosed in JP 2000-283281 A, it is necessary to provide the selector switch that changes the mode between the automatic mode and the manual mode at the steering wheel. Accordingly, the circuit wiring of the steering wheel, etc., becomes complex.
According to the selector device that is a prior art disclosed in FIG. 8 of JP 2007-232093 A, it is necessary to provide exclusive manual operation path and manual mode position (M) for a manual operation, so that the selector device becomes complex.
Hence, JP 2007-232093 A discloses, in FIGS. 1 to 5, a prior art that is a control device for an automatic transmission which can be operated in first or second manual mode different from each other with the select position of the selector device being maintained in the forward position including a first forward position and a second forward position. According to this prior art, for example, the first and second forward positions are arbitrary select positions of the selector device which cause a vehicle to run forward, respectively, such as a drive position, a low position, a D2 position, and a D3 position.
Also, the steering wheel includes operation means that is a shift-up switch which commonly shifts up the first manual mode and the second manual mode and a shift-down switch that commonly shifts down those modes. When the control device detects that either one of the shift-up switch or the shift-down switch is operated, the automatic mode is changed to the first manual mode or the second manual mode corresponding to the select position of the selector device.
Meanwhile, JP 2007-232093 A also discloses a prior art which causes the automatic transmission to return to an original automatic mode like a drive range when a certain time elapses after the selector device is set to a position corresponding to the first manual mode.
Also, JP 2007-118759 A (see FIGS. 1 and 2) discloses a technology for a range-change control device of an automatic transmission. According to this range-change control device, right and left paddle switches are provided at the right and left of the steering wheel as a selector device in addition to a parking switch. The right and left paddle switches are operable back and forth, and the range-change control device is configured to detect in which direction each paddle switch is operated in the backward direction or the forward direction.
According to this range-change control device for an automatic transmission, when a transmission controller detects the simultaneous backward operation to the right and left paddle switches, it is determined that the range is changed to a reverse (“R”) range in order to control the automatic transmission. Also, when the transmission controller detects the simultaneous frontward operation to the right and left paddle switches, it is determined that the range is changed to a drive (“D”) range in order to control the automatic transmission.
According to the prior art disclosed in JP 2007-118759 A, when detecting that the right paddle switch is operated in the frontward direction with the automatic transmission being in the D range, the transmission controller determines that a manual shift range M+ (manual shift-up range) is selected and performs a control so that the automatic transmission is shifted up by one gear range every time the frontward operation to the right paddle switch is detected. Likewise, when detecting that the left paddle switch is operated in the frontward direction with the automatic transmission being in the D range, the transmission controller determines that a manual shift range M− (manual shift-down range) is selected and performs a control so that the automatic transmission is shifted down by one gear range every time the forward operation to the left paddle switch is detected.
However, according to the prior art disclosed in FIGS. 1 to 4 of JP 2007-232093 A and the prior art disclosed in FIGS. 1 and 4 of JP 2007-118759 A, when the automatic transmission is in the D range, if a driver falsely touches either one of the shift-up switch or the shift-down switch provided at the steering wheel, or when the driver falsely touches either one of the right paddle switch or the left paddle switch, the automatic transmission is changed to a manual mode that is not intended by the driver, so that the driver may feel strangeness.
The present invention is made in order to overcome the problems of the above-explained prior art, and it is an object of the present invention to provide a control device for an automatic transmission which is capable of changing a mode of the automatic transmission between an automatic mode and a manual mode while a driver keeps holding a steering wheel with the select position of a selector device being in a forward position, and which is capable of surely changing the mode intended by the driver between the automatic mode and the manual mode.